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Esquivel D.,Center for Ordered Materials | Kaczmarek A.M.,Ghent University | Jimenez-Sanchidrian C.,University of Cordoba, Spain | Van Deun R.,Ghent University | And 2 more authors.
Journal of Materials Chemistry C

A periodic mesoporous organosilica (PMO) functionalized with dipyridyl-dihydropyridazine units has been successfully prepared by a hetero Diels-Alder reaction between the double bonds of an ethenylene-bridged PMO material and a substituted tetrazine. The ordering and mesoporosity of the parent material is maintained after the post-modification process, and the surface Diels-Alder adducts are clearly observable in the pores. These dipyridyl-dihydropyridazine moieties can form interesting chelates with lanthanide ions. Thus, two novel organic-inorganic luminescent hybrid materials have been obtained by linking of Eu3+ compounds to an ethene-PMO functionalized with dipyridyl-dihydropyridazine. Both materials have been studied in depth by photoluminescence spectroscopy and luminescence decay time measurements. Our results reveal the key role of surface Diels-Alder adducts as suitable sensitizing ligands for europium ions. © 2015 The Royal Society of Chemistry. Source

Lopez M.I.,University of Cordoba, Spain | Esquivel D.,Center for Ordered Materials | Jimenez-Sanchidrian C.,University of Cordoba, Spain | Romero-Salguero F.J.,University of Cordoba, Spain | Van Der Voort P.,Center for Ordered Materials
Journal of Catalysis

The synthesis and catalytic activity of a new sulfonic acid-functionalized periodic mesoporous organosilica (PMO) obtained by an in situ oxidation process have been reported. This material was prepared by co-condensation of a homemade thiol-functionalized bis-silane precursor (EtO)3Si-R-Si(OEt)3 (R = CH2CHSH) with 1,2-bis(triethoxysilyl)ethane (BTEE) in the presence of a nonionic triblock co-polymer. Thiol groups were oxidized either in situ during the formation of the mesostructure, or by a post-synthesis oxidation of the solid material. The in situ generated sulfonated PMO material had a well-ordered hexagonal mesoporous structure and a narrow pore size distribution. The sulfonic acid concentration of these materials was in the range of 0.85-1.48 mmol H+ g-1. The catalytic performance of these sulfonic acid-functionalized materials was evaluated and compared with the commercial resin Amberlyst-15 in the esterification of acetic acid with benzyl alcohol. The in situ sulfonated PMO has shown to be an efficient, robust, and recyclable catalyst in acid-catalyzed reactions throughout consecutive catalytic cycles. © 2015 Elsevier B.V. All rights reserved. Source

Van Der Voort P.,Center for Ordered Materials | Leus K.,Center for Ordered Materials | Liu Y.-Y.,Center for Ordered Materials | Vandichel M.,Ghent University | And 3 more authors.
New Journal of Chemistry

This perspective review paper describes the V-containing metal-organic frameworks that have been developed since the first systematic reports on MOFs almost 15 years ago. These hybrid crystalline materials, containing V(iii) or V(iv) as metal nodes, show interesting behavior in oxidation catalysis and gas sorption. A significant amount of papers has appeared on the use of these structures in gas (hydrocarbon, CO2) separation. Promising future research and development of V-MOFs is suggested. © 2014 The Partner Organisations. Source

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